CVE-2025-47169 is a high-severity heap-based buffer overflow vulnerability identified in Microsoft SharePoint Enterprise Server 2016, specifically version 16.0.0. The vulnerability stems from improper handling of memory buffers within the Microsoft Office Word component integrated into SharePoint. An attacker can exploit this flaw by crafting a malicious Word document that, when processed by the vulnerable SharePoint server, triggers the overflow condition. This overflow allows an unauthorized attacker to execute arbitrary code locally on the affected system. The vulnerability does not require prior authentication (PR:N) but does require some user interaction (UI:R), such as opening or previewing a malicious document. The CVSS v3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability (all rated high). The attack vector is local (AV:L), meaning the attacker must have local access or be able to induce the vulnerable code execution locally, for example through a user opening a malicious file. The vulnerability is classified under CWE-122, indicating a heap-based buffer overflow, which can lead to memory corruption and arbitrary code execution. Currently, there are no known exploits in the wild and no patches publicly available, which increases the risk for organizations that have not implemented mitigations or workarounds. Given the integration of Microsoft Office Word functionality within SharePoint Enterprise Server 2016, this vulnerability could be leveraged to compromise enterprise collaboration environments, potentially leading to data breaches, privilege escalation, or disruption of services.

For European organizations, the impact of CVE-2025-47169 could be significant, especially for those relying on Microsoft SharePoint Enterprise Server 2016 for document management and collaboration. Exploitation could lead to unauthorized code execution on critical servers, resulting in data theft, alteration, or destruction, and potentially disrupting business operations. Confidential information stored or processed via SharePoint could be exposed, violating GDPR and other data protection regulations, leading to legal and financial repercussions. The requirement for local attack vector and user interaction somewhat limits remote exploitation, but insider threats or social engineering attacks could still trigger the vulnerability. Organizations in sectors such as finance, healthcare, government, and critical infrastructure, which heavily depend on SharePoint for document workflows, are particularly at risk. The absence of known exploits in the wild provides a window for proactive defense, but the lack of available patches necessitates immediate risk mitigation to prevent potential future exploitation.

Given the absence of official patches, European organizations should implement targeted mitigations: 1) Restrict and monitor access to SharePoint Enterprise Server 2016, limiting user permissions to the minimum necessary to reduce the likelihood of malicious document processing. 2) Disable or restrict the preview and automatic rendering of Word documents within SharePoint to prevent automatic triggering of the vulnerability. 3) Employ application whitelisting and endpoint protection solutions capable of detecting anomalous behavior indicative of exploitation attempts. 4) Conduct user awareness training to reduce the risk of social engineering attacks that could lead to opening malicious documents. 5) Implement network segmentation to isolate SharePoint servers from less trusted network zones, minimizing lateral movement opportunities. 6) Monitor logs and system behavior for signs of heap corruption or unusual process activity related to Word or SharePoint services. 7) Plan and prioritize upgrading or patching to a supported SharePoint version once a security update becomes available from Microsoft. 8) Consider deploying virtual patching via web application firewalls or intrusion prevention systems that can detect and block exploit attempts targeting this vulnerability.